A107263 Position where n (presumably) appears the last time in A032531, or 0 if n keeps appearing.

20678, 95695, 120724, 133876, 1148205

Offset: 0

Author

Ralf Stephan, May 15 2005

Keywords

• nonn
• hard
• more

Comments

The sequence resulted from analysis of A032531(n), n<= 2*10^6.

We can only speak of provisional values and, in the absence of any proof, I am not sure how rigorous these results are for n > 2*10^6. - Herman Jamke (hermanjamke(AT)fastmail.fm), Nov 03 2006

I extended the analysis of A032531(n) to all n<= 10^7. Same comments apply considering the new limit and, of course, the uniqueness of Stephan's sequence remains as always only a conjecture since there's no proof that the sequence should be anything different from the zero sequence for all, most or even any of the terms - Herman Jamke (hermanjamke(AT)fastmail.fm), Nov 08 2006

Search extended to the first 10^9 terms of A032531. - Andrew Howroyd, Nov 12 2024

Crossrefs

Cf. A107262.

Programs

PARI

\\ Warning: conjectured sequence.
accrows(n)={my(v=vector(n), p=vector(n), idx=0); for(i=1, n, for(j=1, i, my(t=v[j]+1); if(t<=n, v[t]++; p[t]=idx); idx++)); p}
\\ search 5000 rows of A032531 (first binomial(5000+1,2) = 12502500 terms).
{ accrows(5000)[1..31] } \\ Andrew Howroyd, Nov 12 2024

Extensions

Corrected and extended by Herman Jamke (hermanjamke(AT)fastmail.fm), Nov 03 2006, Nov 08 2006